That is the same error you get when trying to change an enlisted send port to (or from) ordered delivery.

Our situation was weird though, as the existing application had been created using the exact same binding file. Meaning, we have a binding file that can be imported once, but not twice.

The reason for this is rather subtle. Created by a hand the binding file configuring the ordered send port looked somewhat like this:

<SendPort ...>

...

<PrimaryTransport>

...

<OrderedDelivery>false</OrderedDelivery>

...

</PrimaryTransport>

<SecondaryTransport>

...

</SecondaryTransport>

...

<OrderedDelivery>true</OrderedDelivery>

...

</SendPort>

Note how ordered delivery of the primary transport is set to false while ordered delivery is set to true on the send port itself. This will create a send port with an ordered primary transport on first import, but a second import will make the import fail with the error above.

The solution is to keep the OrderedDelivery tag of the send port in sync with that of the Primary transport